12
Man, as a rational free being, can and must reread with discernment that biological
rhythm which belongs to the natural order. He can and must conform to it so as to
exercise the “responsible parenthood,” which, according to the Creator’s design, is
inscribed in the natural order of human fecundity. The concept of a morally correct
regulation of fertility is nothing other than the rereading of the “language of the body” in
truth. The very “natural rhythms immanent in the generative functions” pertain to the
objective truth of that language, which the persons concerned should reread in its full
objective content. 37 (italics in original)
In St. John Paul II’s exhortation as well as in the document, Humanae Vitae, the authors make
clear that natural birth regulation should not be viewed as a necessary evil in cases of serious
reasons for avoiding pregnancy, but rather as an irreducible expression of the couple’s
participation in the divine life in its unitive and procreative dimensions. Fertility awareness is
intrinsic to the meaning of responsible parenthood, as well as necessary to a full expression of
man’s dignity as a creature endowed with intellect and will. Moreover, the language of fertility is
an integral dimension of the couple’s dialogue as embodied persons in their one-flesh union in
marriage.
Practically speaking, this dialogue regarding shared fertility finds its context in the
natural rhythms of a woman’s monthly cycle, since a man is in general always fertile, and a
woman is infertile most of the time. 38 St. John Paul II explains that this practical context points
to a more profound theological reality present in the woman not only in her external anatomy,
but “even in the deepest bio-physiological determinants.” 39 Specifically, it is in the woman’s
body that conception and gestation occur; consequently, it is here that the mystery of creation has
its beginning, both in its biological and in its theological dimensions. In the generative process
37
John Paul II, “Responsible Parenthood Linked to Moral Maturity,” Vatican.va, September 5, 1984, sec.
1, accessed May 27, 2018, https://w2.vatican.va/content/john-paul-ii/it/audiences/1984/documents/hf_jp-
ii_aud_19840905.html.
38
Thomas Hilgers et al., The Creighton Model of FertilityCare™ System: A Standardized Case
Management Approach to Teaching, Book 1, 2nd ed. (Nebraska: Pope Paul VI Institute Press, 2002), 43.
39
John Paul II, “The Mystery of Woman is Revealed in Motherhood,” Vatican.va, March 12, 1980, para. 6,
accessed May 27, 2018, https://w2.vatican.va/content/john-paul-ii/en/audiences/1980/documents/hf_jp-
ii_aud_19800312.html.